From what i have learned about these little tractors is that the onan engine is not cheap when it comes time to work on it. However the one in this one seems to be in fine shape, i hope that it continues to be that way. It is my understanding that a complete rebuild will cost around 1700.00. The whole tractor is pretty much bullet proof. The design of them hasnt changed much over the years. Parts arent real expensive, but when you are buying alot of them it sure adds up. There are several trator forums dedicated to the case garden tractors, and you can get alot of help there. I bought all of my parts from a dealer in MI and just had them mailed to me. If you ever run accross Brian Hildreth in the case forums, you can count on him to help you out.
As far as what one would be worth, i really dont know what to say. I guess it depends on the condition and how much you want it. To be truthfully honest, i would not have bought this thing if i knew how much it was gonna cost to fix it up. Now that i have done it though, i should have a very dependable tractor for years to come. I just need to take very good care of that engine. This tractor was built in 1979 and it will probably be still running when i kick the bucket.
There are lots of attachments that can be used with these tractors. I have a sleeve hitch on this one, but 3pt are available. The front end have a quick attach system to bolt on snow blowers, push blades, and hydravacs. I didnt get a deck with mine and probably will not have one in the forseeable future, due to the fact that most of the hardware is up north. I bought mine mainly to keep up with the ruts that are caused by the water running acrross my property.